to the Banks of Newfoundland, and the northern 

 coasts of Europe. The observation, that the 

 proximity of a sand-bank is indicated by a rapid 

 descent of the temperature of the sea at it's sur- 

 face, is not only interesting to the naturalist, but 

 may become also very important for the safety 

 of navigators. The use of the thermometer ought 

 certainly not to lead us to neglect the use of the 

 lead ; but the experiments, which I shall mention 

 in the course of this narrative, sufficiently prove, 

 that variations of temperature, sensible to the 

 most imperfect instruments, indicate danger long 

 before the vessel reaches the shoals. In such 

 cases, the frigidity of the water may engage the 

 pilot to heave the lead in places, where he 

 thought himself in the most perfect safety. We 

 shall examine in another place the natural 

 causes of these complicated phenomena ; and 

 shall only here observe, that the waters which 

 cover the shoals owe in a great measure the di- 

 minution of their temperature to their mixture 

 with the lower strata of water, which rise tow- 

 ards the surface on the edge of the banks. 



A heavy sea from the North-west hindered us 

 from continuing our experiments on the tempe- 

 rature of the ocean in the bay of Ferrol. The 

 great height of the waves was the effect of an 

 impetuous wind at sea, and forced the English 

 vessels to retire from the coast. Desirous to 

 avail ourselves of this opportunity of sailing, we 



